Will a 30AH LITHIUM ION BATTERY work for me?

[DonTom]

Not sure what would work for you, but my current battery is in my storage compartment below the rear bunk. I no longer have an onboard generator, so I am going to remote locate the batteries in a box outside in the generator compartment. A little creativity goes a long way as long as you know basic electrical and mechanical skills.
Indeed, double the capacity will take longer to charge. You could upgrade your converter, but it won't do anything for you while boondocking since you don't anything to plug into. I would recommend just plugging in an automotive battery charger when you get back. If your alternator has a high enough output, you could upgrade the wiring from the alternator to charge the batteries in a MH. Mine is only 105A, so I can only charge about 20-30A without dropping voltage for the rest of the vehicle. But when most of our travel times are about 3 hours one way, that should be plenty for me to charge them.

I too have storage space under the rear bed, but it stays quite full as it is. But yeah, if I want to do it badly enough, I am also sure I could come up with something for another battery box.


My generator crapped out on this trip (mentioned in the tech section  here), but when I have it working again, that is what I can "plug into" when boondocked.


BTW, when I started this trip, I had two Trojan T-105's (6 volt, 225AH). While in Death Valley, I lost a couple of volts from one of them, as if a cell shorted out out whatever.  So I drove to Wal*Mart in Pahrump, NV  and replaced them both with what they had, a 12 volt  114AH (at 1 amp) Marine battery. But it was a much better fit in my box. The six volt batteries were a real hassle to deal with in my box as they go right to the edge and had no easy way to get out. Kinda was a big job just getting them out. The new 12 volt battery is very easy to deal with but half the AHs.


-Don-  Barstow, CA (Salton Sea SRA  is all closed down).

 

[Tom55555]

I don't use mine just because the only thing we ever use it for is microwave popcorn. But my wife prefers smart food cheddar popcorn more anyways, so I just took it out for more storage. Our coffee maker runs off of the burner on the stove. We use a small inverter for the TV at bedtime for the kids, otherwise we don't need electric for anything except AC in the middle of the summer to keep the dogs cool while we are out.

We really only use our generator when boondocking maybe an hour a day, more if it's hot for the AC. 

My wife drinks coffee and likes to cook outside with electric skillets. She has two of them; one flat and one with a 3" lip. I'm convinced she can cook anything. She fills the freezer with microwave stuff like Stouffers.

I like to cook on an open fire but sometimes the weather doesn't cooperate. Those generators are handy.

 

[DonTom]

I like to cook on an open fire but sometimes the weather doesn't cooperate. Those generators are handy.

Large inverters can be handy also, such as after my generator crapped out on this trip! I was still able to make my coffee and use the microwave oven when I was boondocked at Organ Pipe Cactus Nat'l Mon for ten nights.


No need for an AC there  in December!


-Don-  Barstow, CA

 

[Tom55555]

Large inverters can be handy also, such as after my generator crapped out on this trip! I was still able to make my coffee and use the microwave oven when I was boondocked at Organ Pipe Cactus Nat'l Mon for ten nights.


No need for an AC there  in December!


-Don-  Barstow, CA

DonTom, How many Ah do you have?

 

[DonTom]

DonTom, How many Ah do you have?

For now, only 114 AH (at one amp) from a new battery, no more than a month old. One of my two Trojan T-105 six volt batteries (225 AH) crapped out on this trip. Shorted cell (two volts low  five minutes after after a long charge). So from Death Valley, CA , where I was boondocked at the Sunset Camp, I drove to the Wal*Mart in Pahrump, NV to get to a new Wal*Mart 12 V Marine battery, which is the best they had for a RV  house battery. 


I am considering changing it, undecided on what to do between the higher voltage 12 volt  Lit-Ion (only 100 AH) or the much higher AH of the Trojans that  are very difficult to deal with in this RV.  At least the one 12 V battery in there now is a good fit.


-Don-  Barstow, CA

 

[Lou Schneider]

I put a pair of the Lion Safari UT1300s in my motorhome when Costco had them on sale for $700 each, now you can get SOK 100 a/h batteries for $570 and they have very good reviews.

Lithium is a no-brainer on everything but price.  You'll get 80% or better of the rated capacity if you plug and play them with an existing 13.5 volt lead acid converter.  Raise the converter to 14.1 or 14.6 volts and they'll charge the rest of the way.  Letting them sit with a partial charge won't hurt them.  You can safely discharge lithium batteries to their full rated capacity.  They have higher voltage output that's more flat over the entire discharge cycle - they respond about the same at 20% state of charge as they do at at 80% SOC, i.e. they don't fade as they discharge.  And, of course they're totally sealed so there's absolutely no maintenance, no corroded connections, etc.

At $570 for 100 a/h usable capacity, the price of the SOK battery is approaching the cost of a pair of 100 a/h AGM batteries.  And a single 100 a/h lithium battery has the same usable capacity as a pair of 100 a/h AGMs or about 20% less usable capacity than your golf cart battery pair since you can't safely discharge lead acid below 50%.

 

[DonTom]

Lou, You just did a great  job of talking me into the Lith-ion battery. I will have one before my next RV trip


Thanks for that info. That was exactly the type of info I wanted to the point of me having no questions.




-Don-  Barstow, CA

 

[Tom55555]

Your coach battery doesn't need much power unless you're watching TV. When boondocking, if you use your hot spot phone and tablets you will have all the power you need with a standard 100 Ah lead acid battery. AC and microwave is a different subject and has nothing to do with batteries in my opinion. 55 gallons of gas will keep your batteries charged for a long time.

 

[Mark_K5LXP]

At $570 for 100 a/h usable capacity, the price of the SOK battery is approaching the cost of a pair of 100 a/h AGM batteries.

You're wrong about the "safely" discharging lead acid below 50% but depending on your use model the price point of these lithiums could easily put them in the lead if you're already running AGM's, especially the spendy premium brands.  Another 25-30% reduction in price and they'll be contenders to replace flooded.  The only issue I see is transient load response.  Lead acid can deliver a pretty serious surge power but equivalent size lithiums can't.  Not really a problem for most storage applications but it does preclude their use for something like a starting battery.  Surely over time this may change but it's encouraging enough seeing the prices of storage cells coming down.

Mark B.
Albuquerque, NM

 

[DonTom]

our coach battery doesn't need much power unless you're watching TV. When boondocking, if you use your hot spot phone and tablets you will have all the power you need with a standard 100 Ah lead acid battery. AC and microwave is a different subject and has nothing to do with batteries in my opinion. 55 gallons of gas will keep your batteries charged for a long time.

Ham radio stuff is used here often when boondocked, such as when I was at Organ Pipe Cactus Nat'l Mon., AZ for ten days with no AC available at all--not even from my generator as it crapped out on my 2nd day there.  I still got by, fortunately no need to run the furnace there in December!


I ran my 7.4L engine to keep the batteries charged and use my 4.5 KW inverter as needed.  So more gas was wasted too.



-Don-  Barstow, CA

 

[DonTom]

You're wrong about the "safely" discharging lead acid below 50% but depending on your use model the price point of these lithiums could easily put them in the lead if you're already running AGM's, especially the spendy premium brands.  Another 25-30% reduction in price and they'll be contenders to replace flooded.  The only issue I see is transient load response.  Lead acid can deliver a pretty serious surge power but equivalent size lithiums can't.  Not really a problem for most storage applications but it does preclude their use for something like a starting battery.  Surely over time this may change but it's encouraging enough seeing the prices of storage cells coming down.

Mark B.
Albuquerque, NM

Not all the Lit-Ion battery designs are the same. For an example, with Zero electric motorcycles, the older batteries (before year 2016) are best to store at 100% charge. The newer batteries are stored at 60% SOC, and should be recharged quickly (within 24 hours) whenever  they fall below 30% SOC, from either storage or from use.  However, I am not sure how these 116.5 volt batteries compare to 12 v batteries.


I also wondered about engine starting using the Lit-Ion. I assume they will still do the job, won't they, when the engine battery gets weak?


-Don-  Barstow, CA

 

[Lou Schneider]

The only issue I see is transient load response.  Lead acid can deliver a pretty serious surge power but equivalent size lithiums can't.

I agree lithiums aren't suited for starting battery service, but when my starting battery suddenly died on a trip my pair of UT1300 house batteries had no problem starting the motorhome's 7.4L gas engines several times using the Boost switch.  After I got the battery out (not a simple procedure on a Safari motorhome) I found the failure was an internal open between the battery's top and side posts so it was completely out of the circuit.  Since I was in the middle of Nowhere, Nevada when it failed and I had a toad I could use for a jumpstart if needed, I decided to wait until I got to the land of inexpensive batteries (Walmart) before buying a replacement.  And no, the failed battery wasn't from Walmart, it came with the motorhome. 

 

[DonTom]

I agree lithiums aren't suited for starting battery service, but when my starting battery suddenly died on a trip my pair of UT1300 house batteries had no problem starting the motorhome's 7.4L gas engines several times using the Boost switch.

That was exactly what I assumed, as all true deep cycle batteries are not designed to start engines--but they do fine anyway, for the occasional use. I find the good ones have no spec for starting engines, but they get the job done.  Besides, I don't find that issue to be that important (in most cases) as I carry a ten amp charger with me that I can run from my generator (when the generator works--unlike right now!).  I also plan on using it, if my alternator craps out to get help get me going to a place where I (or some shop) can change it.

Now if there was only a backup for an in-tank fuel pump--But that was last year. I am at the same rest stop right now that I was last year on NYD when my fuel pump crapped out.

-Don-  Turlock, CA

 

[DonTom]

BTW, do these 12V Lit-Ion batteries have a BMS inside them as do EV batteries? And a non-replaceable fuse? Or are they just cells?


-Don-  Turlock, CA

 

[Mark_K5LXP]

Can't speak to all, but any I've researched (Battleborn being one) have built in BMS and charge/discharge self protection.

Mark B.
Albuquerque, NM

 

[Lou Schneider]

All of the batteries sold as drop-in replacements have a built-in BMS.  They have to, since they're sealed and have no access to the individual cells.

If you're interested in more information, a young guy named Will Prowse has numerous videos on YouTube.  He's become a self-educated savant on lithium batteries, purchasing and disassembling several to see what's inside.

 

[DonTom]

All of the batteries sold as drop-in replacements have a built-in BMS.  They have to, since they're sealed and have no access to the individual cells.

If you're interested in more information, a young guy named Will Prowse has numerous videos on YouTube.  He's become a self-educated savant on lithium batteries, purchasing and disassembling several to see what's inside.

I will check those videos when I get home.


Do you know if they contain a non-replaceable fuse?  And does the BMS balance the cells at the very end of a full charge? If so, how do your cells get balanced since you don't charge to full?


-Don-  Turlock, CA

 

[Lou Schneider]

All of the batteries Will has torn down have overcurrent relays that cut out around 100 amps and reset when the BMS senses charging voltage on the battery terminals.  Yes, the BMS balances the cells and blocks charging current if the battery temperature drops below freezing.

 

[Obiwan Canoli]

If i may add something to the discussion...

I researched Lithium batteries, along with each alternative, when I replaced my four house batteries, wet cells, Deep Cell, but not AGM... I fo.und that the life expectancy, durability, weight, and SOC issues pointed to only one option for me - Lithiums were the best choice, and the least I would consider was my requirement that each battery be rated at no less than 100Ah. At the same time I installed the Li's, I also installed a Victron 712 Voltmeter to monitor battery power, and a Controller with increased wattage/Amp capacity (for future solar panel additions).

Very happy with my choice here. LI's may not be for everyone, but in my case, they were the best option

 

[John From Detroit]

That is a lawn tractor sized battery. Note the 30AH. I suspect your stock battery does better.

One of the fun things about LiFePo4 and most other LI batteries is that you can run 'em down, all the way down, before serious damage happens. that 30 AH battery you can use like 29 of 'em safely. about the same as a Group 29 battery in fact a touch more.